wastewater treatment system · ne reference: cd2069.05 wastewater treatment system revised proposal...

NE reference: cd2069.05

WASTEWATER TREATMENT SYSTEM

Revised Proposal for:

Design, Supply, and Installation of

OPTAER Wastewater Treatment System

Town Perth, ON

March 23, 2016

copyright © Nelson Environmental Inc, 2014

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1.0 Project Overview

An OPTAER Wastewater Treatment system is proposed for the Town Perth, ON as an upgrade for the existing lagoon treatment system with the objective of ammonia reduction, fecal and total coliform reduction as well as CBOD/TSS polishing. The design would allow for increased hydraulic flows and influent loads. The design is based on the results of the SAGR pilot operated at Perth from 2012-2013. The SAGR beds would be constructed in existing dry Cell 4, with construction taking place in two phases. This proposal presents pricing for Phase 1 only. Phase 1 – Design Year 2030:

Retain the existing lagoon system for primary and secondary treatment. Existing cells are to provide BOD/TSS peak levels generally not exceeding 30/40 mg/l.

Construct a low lift pump station following Cell 3 to transfer water to the new SAGR beds (by others).

Implement a six (6)-cell aerated Horizontal Flow Submerged Attached Growth Reactor (SAGR®) for nitrification (ammonia removal), BOD, and TSS polishing following the existing lagoon system.

Implement a UV Disinfection system prior to discharge if required (by others).

Phase 2 – Design Year 2041:

Construct one (1) SAGR bed following the lagoon system

Implement OPTAER fine bubble aeration in the existing lagoon Cells 1 and 2. Cell 3 would remain as facultative.


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2.0 System Design Parameters

Projected design loads and flows, as well as effluent requirements are summarized in the following table:

SAGR ACS SAGR

Phase 1 Phase 2 Influent requirements Effluent

Design Flow m3/day 7,055 8,349

cBOD mg/L 99 107 <30 <20 <10

TSS mg/L 99 107 <40 <15

TKN mg/L 25 25 <25

TAN mg/L *2/4 <1*/3

*Summer/winter

Lagoon Influent

SAGR aeration design parameters are summarized in the following table:

SAGR Aeration System

Phase 1

Alpha 0.70

Beta 0.95

Theta 1.024

Site elevation (m) 133Min. Dissolved Oxygen (mg/l) 3.0Water height (m) 2.5

SAGR Loading Rate (g BOD/m2/day) 78.4

SAGR Loading Rate (lbs NH3/1000 ft3) 0.407

Total SCFM (design) 2,799 Lagoon sizes and retention times in Phase 1 are shown in the following table:

WaterApproximate

WaterRetention

depth Volume* time

Cell Basin Type (m) (m3) (days)

1 Facultative 1.50 142,000 20.1

2 Facultative 1.50 142,000 20.1

3 Facultative 1.50 137,250 19.5

*estimated due to irregular shape 421,250 59.7


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3.0 OPTAER Treatment Process

i. Submerged Attached Growth Reactor (SAGR) The Submerged Attached Growth Reactor (SAGR) is a patented process designed to provide nitrification (ammonia removal) in cold to moderate climates. The SAGR is essentially a clean aggregate media bed with evenly distributed wastewater flow across the width of the cell, and a horizontal collection chamber at the back end of the system. LINEAR aeration throughout the floor of the SAGR provides aerobic conditions that are required for nitrification. The gravel bed is covered with a layer of peat or mulch to prevent freezing. The following variables need to be considered during nitrification design:

Dissolved Oxygen Levels - Nitrifying bacteria require aerobic conditions. A minimum dissolved oxygen concentration of 3 mg/L must be present for the process to fully occur.

BOD concentration – Nitrifying bacteria require low BOD concentrations to be effective. Primary BOD removal occurs in the upstream lagoon system. The SAGR provides additional BOD polishing if necessary to reduce BOD concentrations below 25 mg/l.

Surface area - Bacteria require a medium of some form to grow on. High surface area medium allows for higher-density nitrifying bacteria population.

Bacteria - In order to convert ammonia (NH3) to nitrite (NO2-) and ultimately nitrate (NO3

-) (nitrification) sufficient quantities of two bacteria are required, Nitrosomonas and Nitrobacter.

Alkalinity - The nitrification process reduces pH levels and consumes alkalinity. In order for nitrification to occur, 7.1 mg of alkalinity must be available for each mg/L of ammonia removed

Temperature - Nitrification in a SAGR occurs at water temperatures as low as 0.5oC. The long sludge age inherent in an attached growth system allows for full nitrification at temperatures where bacteria reproduction is greatly inhibited.

pH - Nitrification is enhanced at higher pH levels. pH levels of 7.5 to 8.5 are ideal, although nitrifying bacteria can adapt outside of this range.

All SAGR cells are operated in parallel (six (6) cells in Phase 1, seven (7) cells in Phase 2). Piping allows any cell to be isolated and bypassed.


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4.0 Aeration Process Equipment

i. Air Supply and Header System

Air supply for the treatment system is provided by positive displacement blowers. Galvanized metal manifold/discharge piping is used to dissipate the heat produced by the blowers. Shallow buried HDPE header piping connects to the galvanized metal header, and supplies air to the SAGR laterals. The header has flanged connections for each lateral as shown on the drawings.

ii. SAGR HDPE Header & Feeder System

High Density Polyethylene (HDPE) laterals run along the top on each side of the SAGR. The laterals are located in the top layer of insulating mulch. All HDPE piping connections and fittings are thermally fused to ensure maximum strength and durability. A shallow buried HDPE header connects blowers to the SAGR laterals. HDPE service saddles are thermally fused to the lateral piping for each diffuser line. HDPE drop legs provide air to the individual diffuser lines. All header and feeder piping is designed to accommodate increased airflow for high pressure and volume cleaning without increasing header friction losses by more than 1 psi. This allows for management of additional organic load, improved diffuser maintenance and additional odor control.

iii. Submerged Attached Growth Reactor (SAGR) LINEAR Aeration System

LINEAR coarse bubble diffusers are used to provide oxygen to the wastewater. Diffuser lines are manufactured from LDPE (Low Density Polyethylene) with reinforced air releases along the tubing. The diffuser tubing is designed for direct burial in the SAGR bed. The diffuser locations have been spaced according to the projected oxygen demand in the SAGR. The design diffuser distribution is critical to ensure that nitrification occurs. In addition to providing oxygen for nitrification the proposed aeration system brings numerous other long-term performance benefits to this sub-surface flow system.

Full aeration grid ensures that wastewater channeling cannot occur in the gravel layer (maximize retention time and media contact).

Sludge digestion in gravel layer is enhanced due to aerobic conditions.

Year-around odor free operation.


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iv. Positive Displacement Blowers

Positive displacement blowers are used to provide air supply for the OPTAER treatment system. Blowers are designed to provide the required airflow at normal system operating pressure, and have the capability of operating at the maximum required pressure intermittently for diffuser purging. The blowers are equipped with sound attenuating enclosures. Blower requirements are summarized in the following table:

*VFD control used to reduce blower speed for Phase 1

SAGR

Blowers Phase 1

Number of blowers total 3

Number of blowers on duty 2

Number of blowers on standby 1

Motor nameplate horsepower hp 100

Design airflow per blower SCFM 1400*

Normal operating pressure psi 5.8

Maximum required pressure psi 8.8

Actual Power Consumption bhp 55.6

Actual Sound level dB(A) 74


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5.0 Capital Cost

Included in the Submerged Attached Growth Reactor (SAGR) capital cost are:

NEI System Process Design (Ontario P. Eng. Stamped) Process CAD drawings and specifications (Ontario P. Eng. Stamped)

SAGR Aeration lateral piping, feeder piping, diffusers, valves, and fittings as required

HDPE shallow buried main air supply header

SAGR Influent distribution and effluent collection chambers

Blower control panels (including VFD speed control)

Galvanized metal blower header and connection pipe (heat dissipation)

Three (3) 100 hp positive displacement blowers with sound attenuating enclosures

SAGR Process equipment installation /start-up /commissioning /training

Operation and maintenance manuals

As-built Drawings Items Specifically Not Included:

Equipment and material required for Phase 2

Material offloading and on-site storage

Civil works including SAGR cell design and construction, cell liner, transport piping, inter-cell piping, discharge piping, manholes, valves, access roads to site, site roads and landscaping, etc.

Lift station to supply SAGR

Building to house blowers, including concrete, electrical, and HVAC

Materials and construction required for the SAGR: o granular material o insulating peat or mulch o Influent flow splitter chamber with flow control weirs

Power hookup to building

Restoration Budgetary cost for the design, supply, and installation of the OPTAER SAGR process equipment:

Phase 1 -

All budgets are subject to final design review. All budgetary prices include shipping to jobsite but do not include taxes.

Budget prices are valid for 90 days.


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6.0 Civil Works Required for OPTAER Implementation

The intent of this proposal is not to provide details regarding civil works required but rather to provide a general overview as to the anticipated scope of work. The following quantities are not included in the Nelson Environmental scope of work, but are provided below for cost estimation purposes.

Construct new SAGR cells

Construct inter-cell piping for SAGR

Construct discharge control structure after SAGR

Materials and construction required specifically for the SAGR (estimated material quantities are shown in the following tables):

Phase 1:

Item Description UOM Quantity

Uniform Graded Clean Rock m3 31,490

Insulating Mulch m3 3,730

Non-Woven Geotextile (8oz) m2 28,160

HDPE Liner (60mil) m2 16,270

Wall Framing & Sheathing m 1,250

Influent Flow Splitter Structure ea 3

Piping, fittings, valves from splitter to SAGR LS 1

Effluent Level Control MH ea 6

Additional Civil Works (As Required)

Common Excavation - Backfill m3 TBD

New Berm Construction m3 TBD

Piping from Lagoon to Splitter LS TBD

Piping from SAGR to discharge LS TBD

Any questions or comments can be directed to:

Nelson Environmental Inc.

5 Burks Way Winnipeg, MB R2J 3R8

Tel: 204-949-7500 Fax: 204-237-0660

FUTU

RE

CELL #3EXISTING FACULTATIVE



PROPOSED AERATION LAYOUT - PHASE 1SCALE: 1:1750

PROPOSEDBLOWER LOCATION

INFLUENT INFLUENT

PROPOSEDSAGR LOCATION(TYPICAL OF 6 CELLS)

LOW-LIFTPUMP STATION

OUTFALL TOTAY RIVER

FUTU

RE

PROPOSED SAGRLOCATION(TYPICAL OF 6 CELLS)

31

SEE PLAN

TYPICAL SECTION - AERATED CELLSSCALE: N.T.S.

FREEBOARD1.00m

WATER DEPTH1.50m

SEE PLAN

1

3

NOTE:

TYPICAL SAGR CONSTRUCTIONSCALE: N.T.S.

BACKFILL TO OCCUR SIMULTANEOUSTO SAGR AGGREGATE PLACEMENT

SUPPORT WALL/GEOMEMBRANE LINER

INSULATINGMULCH LAYER

AGGREGATE

SAMPLE GROUNDLINE

EXCAVATION DEPTH FROM EXISTINGGROUND LEVEL SHOWN FOR ILLUSTRATIVEPURPOSES ONLY. FINAL EXCAVATIONDEPTHS TO BE DETERMINED AFTER SITE SURVEY

WATER DEPTH2.50m

5 BURKS WAY

WINNIPEG, MANITOBA

CANADA R2J 3R8

NELSON ENVIRONMENTAL INC.

Ph: (204) 949-7500

Fax: (204) 237-0660

www.nelsonenvironmental.com

DRAWN BY:

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SCALE:APPROVED BY:

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copyright © Nelson Environmental Inc., 2015

PERTH, ONPROPOSED WASTEWATER TREATMENT SYSTEM

PROPOSED OPTAER SYSTEMPROPOSED AERATION LAYOUT - PHASE 1, TYPICAL SECTION, LOCATION PLAN

2016/03/23 CD2069.06

AM MH AS NOTEDNE01

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LOCATION PLANSCALE: N.T.S.

wastewater treatment system · ne reference: cd2069.05 wastewater treatment system revised proposal...

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